Device for positioning objects

ABSTRACT

The invention relates to a device for positioning objects in a desired position, said device comprising a transmitter for emitting light rays ( 11 ), a receiver for receiving light rays and an optical sensor ( 10 ) with evaluation unit. The desired position is scanned with the transmitted light rays ( 11 ). The device comprises at least one holding device, in which a predetermined number of objects are stored in predetermined slide-in positions. Each slide-in position is characterized by a position mark. The device furthermore comprises a transport system ( 6 ) for moving the holding device relative to the optical sensor ( 10 ). The holding device is stopped as soon as the position mark for a slide-in position of a predetermined object is detected by the optical sensor ( 10 ), wherein the respective object can be identified with the optical sensor ( 10 ) through the object marks.

[0001] The invention relates to a device for positioning objects in adesired position.

[0002] Devices of this type are generally used in installations withtransport systems, for which the objects must be in predetermineddesired positions for intake, so that they can be processed manually orby a machine.

[0003] One fundamental problem with these arrangements is that objectsnot only must be positioned with the highest possible precision in thepredetermined desirable positions, but that the objects must also beclearly identifiable to avoid confusing the objects.

[0004] Examples of this are machines used to perform analyses of bloodsamples. The blood samples are contained inside individual sample tubes,which are supplied successively to the blood-analysis machine. A sampleis typically removed from the tube inside by inserting a needle throughthe seal on the sample tube and is then analyzed.

[0005] Blood-analysis machines of this type have a high rate ofthroughput, so that a large number of sample tubes per time unit aresupplied to the machine. One critical requirement for performing theanalyses is that the individual sample tubes are clearly identifiableand the analyses can be assigned to the respective sample tubes.Confusing the individual samples could lead to a misdiagnosis for thepatient from whom the blood sample was taken and could ultimatelyendanger the patient.

[0006] To avoid risks of this type, sample tubes are typically providedwith unambiguous markings that can be identified by the operatingpersonnel when performing the blood analysis. To be sure, confusion ofthe individual blood sample tubes can be avoided in this way. However,performing the blood analyses and, in particular, the transport of thesample tubes to the blood-analysis machine must be monitored byoperating personnel. Apart from the fact that human error can stillresult in mistakes when assigning completed analyses to the associatedsamples in the sample tubes, plants of this type require a high numberof personnel.

[0007] It is therefore the object of the invention to provide a devicethat ensures an exact, automatic positioning of objects, wherein a clearidentification and tracking of the objects is simultaneously ensured aswell.

[0008] The features in claim 1 are designed to solve this object.Advantageous embodiments and useful modifications of the invention aredescribed in the dependent claims.

[0009] The device according to the invention for positioning objects ina desired position is provided with an optical sensor, comprising atransmitter for emitting light rays, a receiver for receiving light raysand an evaluation unit. The desired position is scanned with the aid ofthe transmitted light rays. The device is provided with at least oneholding device in which a predetermined number of objects are stored inpredetermined slide-in positions. Each slide-in position ischaracterized with a position mark. The device furthermore comprises atransport system for moving the holding device relative to the opticalsensor. The holding device is stopped as soon as the position mark of aslide-in position for a predetermined object is detected by the opticalsensor, wherein the respective object can be identified by the sensorthrough the object marks.

[0010] The fundamental advantage of the device according to theinvention is that the object not only can be positioned precisely in adesired position by the optical sensor, but the optical sensor alsoensures an unambiguous identification of the objects. At the same time,the objects are also clearly assigned to the slide-in positions in theholding device.

[0011] As a result of the identification of the objects, a confusing ofthe objects is prevented with high certainty. In addition and owing tothe clear assignment of the objects to the slide-in positions in theholding device, an exact localization and tracking of the individualobjects within the conveying system is possible as well.

[0012] One particularly advantageous embodiment of the inventionprovides that the device is a component of an arrangement for analyzingblood. The arrangement comprises a blood-analysis machine, of which onecomponent is a sample-taking device with needle. The objects are sampletubes, closed off with a seal, which contain blood samples. To removesamples from the sample tubes, the needle is inserted through the sealinto the inside of the respective sample tube.

[0013] According to the invention, the sample tubes are suppliedautomatically to the needle, wherein the individual sample tubes aresupplied successively to the sample-taking device, in sample holdersthat form holding devices. The sample tubes are inserted into slide-inpositions in the sample holders.

[0014] Respectively one position mark is arranged on these slide-inunits, which consists of a position barcode and two reference lineelements. The number of the slide-in unit and thus its position withinthe conveying system is encoded in the position barcode. In addition, anobject mark designed as object barcode is respectively arranged on thesample tubes.

[0015] The reference line elements form a target mark, which serves toposition a slide-in unit in the desired position, in which the needle isarranged. The scanning range for the optical sensor during thepositioning in the desired position is advantageously selected such thatonly the position marks at the slide-in units are detected, but not theobject marks.

[0016] As soon as a slide-in unit has been positioned completely in thedesired position, the slide-in unit position is determined in the devicethrough detection of the position barcode. Following this, the scanningrange of the optical sensor is increased, so that the object barcode isalso detected. Not only is it possible to clearly identify the sampletubes and their content in the process, but also the assignment to therespective position barcode. Thus, an unambiguous localization of thesample tube within the transport system is ensured as well.

[0017] Once the slide-in unit is in the desired position, the needle ofthe sample-taking device is inserted into the respective sample tube anda sample is removed from the sample tube for performing an analysis. Theanalysis results are stored together with the information contained inthe associated position barcode and the object barcode, so that theanalysis result can be assigned clearly.

[0018] The transport of the sample tubes to the sample-taking device, aswell as the removal of a sample from the sample tube all occurautomatically and without use of personnel.

[0019] The invention is explained in the following with the aid of thedrawings, which show in:

[0020]FIG. 1: A schematic representation of an exemplary embodiment ofthe device according to the invention, comprising sample holders asholding devices that are conveyed on a transport system and an opticalsensor for positioning sample tubes forming the objects, which arepositioned in a desired position inside sample-holder slide-in units.

[0021]FIG. 2: A view from the side of a sample holder according to FIG.1 with sample tubes stored in slide-in units and positioned outside ofthe desired position.

[0022]FIG. 3: A sample holder according to FIG. 2, with a slide-in unitcontaining a sample tube and positioned in the desired position.

[0023]FIG. 4: A sample holder according to FIG. 2, with an emptyslide-in unit positioned outside of the desired position.

[0024]FIG. 5: A sample holder according to FIG. 2, with an emptyslide-in unit positioned inside the desired position.

[0025]FIG. 1 schematically shows an exemplary embodiment of the deviceaccording to the invention for positioning objects in a desiredposition.

[0026] In the present case, the device forms a component of anarrangement 1 for analyzing blood. The objects are sample tubes 2,preferably containing blood samples, which are respectively sealed onthe top with a seal 3 in the form of a cork. The sample tubes 2 arestored in several sample holders 4 that form holding devices for theobjects. The individual sample holders 4 have identical designs andrespectively contain a predetermined number of slide-in units 5. Theslide-in units 5 are also identical and hold respectively one sampletube 2.

[0027] The sample holders 4 are moved by means of a transport system 6in a conveying direction v and are supplied to a blood-analysis machine7. The blood-analysis machine 7 forms the core of an arrangement 1 foranalyzing blood and is used to analyze blood samples.

[0028] The transport system 6 is a conveying system in which the sampleholders 4 are arranged with predetermined spacing, one behind the other.The sample tubes 2 are positioned vertically inside the respectivesample holder 4. The sample tubes 2 are arranged with verticallyextending longitudinal axes inside the sample holders 4, such that theseals on the tops of sample tubes 2 are freely accessible.

[0029] The sample holders 4 transported on the conveying system aresupplied successively to a sample-taking device 8 that operates jointlywith the blood-analysis machine 7. The sample-taking device 8 preferablyforms a component of the blood-analysis machine 7.

[0030] The sample-taking device 8 is provided with an automaticallycontrolled needle 9 for removing samples from the sample tubes 2. Toremove a sample, the respective sample tube 2 is positioned in a desiredposition directly underneath the needle 9. The desired position in thiscase is a perpendicularly extending straight line S, which extendstransverse to the conveying direction v of the conveying system. Thelongitudinal axis of needle 9 in this case extends along this straightline S.

[0031] As soon as a predetermined sample tube 2 is in the desiredposition, the conveying system is halted and the needle 9 is insertedthrough the seal 3 to remove a sample from the inside of sample tube 2.

[0032] The device for positioning the sample tubes 2 in the desiredposition essentially comprises an optical sensor 10 as well as a controlunit, not shown herein, for actuating the optical sensor 10 and thesample-taking device 8.

[0033] The optical sensor 10 is designed as barcode reader, essentiallycomprising a transmitter for emitting light rays 11, a receiver forreceiving light rays, a deflection unit as well as an evaluation unit.

[0034] The transmitted light rays 11, which are guided over thedeflection unit, periodically scan a scanning range. The barcode readerdetects marks having contrast patterns, which are positioned inside thescanning range. In the process, an amplitude modulation is impressedupon the transmitted light rays 11 that are reflected on the marks, inaccordance with the contrast pattern for the mark. The amplitudemodulation is evaluated in the evaluation unit for detecting the mark.

[0035] The scanning range detected by the transmitted light rays 11extends along the straight line S that forms the desired position. Inprinciple, a scanning range in the shape of a line can be detected withthe light rays 11 that are transmitted by the barcode reader. In thepresent case, a flat grid is scanned with the transmitted light rays 11to detect marks arranged on the sample holder 4 and/or the sample tubes2. The grid forms a rectangular flat element, wherein the size of thisflat element in the plane for the scanned sample holder 4 is adapted tothe dimensions of the marks to be detected.

[0036] The grids scanned by the transmitted light rays 11 and the marksto be detected are shown in FIGS. 2-5.

[0037] FIGS. 2-5 respectively show the side surface of a sample holder4, which is facing the optical sensor 10 and is scanned by thetransmitted light rays 11.

[0038] The sample holder 4 essentially has a cube-shaped contour,wherein the side surface that is facing the optical sensor 10 basicallyforms a flat, rectangular surface. The sample holder 4 shown in FIGS.2-5 contains five identical slide-in units 5 extending in verticaldirection. The slide-in units 5 are arranged equidistant and open on thetop of sample holder 4. The seals of the essentially cylindrical sampletubes 2, positioned in the slide-in units 5, project over the upperedges of the slide-in units 5.

[0039] Position marks are affixed to the undersides of the slide-inunits 5, on the side surface of the sample holder 4, to position aslide-in unit 5 in the desired position. Each position mark assigned toa slide-in unit 5 extends in the direction of the longitudinal axis ofthis slide-in unit 5.

[0040] Each position mark has a position barcode 12. Encoded in thisposition barcode 12 is the number of the respective slide-in unit 5 ofsample holder 4, wherein the slide-in units 5 of all sample holders 4are provided with consecutive numbers. Thus, the position of eachslide-in unit 5 within the complete set of all sample holders 4 of thetransport system 6 is clearly characterized by the respective number. Itis advantageous if the number for a slide-in unit 5 is not onlycontained in the respective position barcode 12 on the slide-in unit 5,but is also affixed in clear text in the form of a number sequence. Theposition barcodes 12 are composed of a series of light and dark lineelements, the longitudinal axes of which extend transverse to thelongitudinal axis of the respective slide-in unit 5 and transverse tothe scanning direction of the light rays 11 transmitted by the opticalsensor 10.

[0041] Each position barcode 12 is provided with a rest zone of apredetermined width at its longitudinal ends. A reference line element13 is positioned in each of these rest zones. The longitudinal axes forthe reference line elements 13 extend parallel to the longitudinal axesof the line elements for the respective position barcode 12.

[0042] The reference line elements 13 forming a target mark constitute acomponent of a position mark and serve to position the respectiveslide-in unit 5 in the desired position.

[0043] An object barcode 14 as object mark is respectively affixed tothe outside of a sample tube 2 and contains the encoded content of asample tube 2.

[0044] Each slide-in unit 5 has an opening 15 in the side surface ofsample holder 4, which surface is facing the optical sensor 10. Theopening 15 is adapted to the size of an object barcode 14, so that thisbarcode is clearly and completely visible through the opening 15 and canbe detected by the optical sensor 10, provided the sample tube 2 ispositioned inside the slide-in unit 5. For this, the longitudinal axisof the opening 15 extends in longitudinal direction of the slide-in unit5.

[0045] A reference barcode 16 for checking whether the slide-in unit 5contains a sample tube 2 is furthermore provided on the inside that ispositioned opposite the opening 15 of each slide-in unit 5. Thereference barcode 16 is visible through the opening 15 if the slide-inunit 5 is empty and thus can be scanned by the optical sensor 10.However, if a sample tube 2 is positioned inside the slide-in unit, thesample tube 2 covers the reference barcode 16, thus preventing thebarcode from being scanned by the optical sensor 10.

[0046] The optical sensor 10 scans the position marks, the object marksand the reference marks, wherein the scanning range of the sensor 10 isa flat grid with a longitudinal axis extending along straight line S,which forms the desired position. The needle 9 of the sample-takingdevice 8 also extends along this straight line.

[0047] The grid width is constant and is given the reference Δd in FIGS.2-5. The optical sensor 10 can be switched between two differentoperating modes. In a first operating mode for positioning a slide-inunit 5 in the desired position, a grid having the width Δd and thelength Δx is scanned with light rays 11 transmitted by the opticalsensor 10. The grid length is adapted to the position marks, such thatthe position marks are completely detected by the optical sensor 10, butthat the object marks and the reference barcodes 16 are outside of thisgrid.

[0048] In a second operating mode for a slide-in unit 5 in the desiredposition, the optical sensor 10 scans a grid with width Δd and lengthΔy. The grid length Δy in this case extends over the complete height ofthe sample holder 4, so that in the second operating mode, the positionmarks as well as the object marks and the reference barcodes 16 aredetected.

[0049] The switch from the first to the second operating mode occurs viaa trigger signal that is generated internally in the evaluation unit assoon as the optical sensor 10 detects that a slide-in unit 5 is in thedesired position.

[0050] The switch from the second to the first operating mode occurs viaan external trigger signal, which is preferably generated inside thecontrol unit and read into the optical sensor 10.

[0051] The operation of the device according to the invention isexplained in the following with the aid of FIGS. 2-5.

[0052] With the arrangement according to FIG. 2, the sample holder 4 ismoved along the conveying direction v, relative to the optical sensor10. For this example, none of the slide-in units 5 are in the desiredposition. The optical sensor 10 is in the first operating mode, so thata grid with length Δx is scanned to detect the position marks.

[0053] The positioning in the desired position is completed once thegrid rests completely on the reference line elements 13 of a positionmark that form the target mark.

[0054] The identically designed reference line elements 13 in this caseare somewhat longer than the width Δd of the grid and shorter than theseal diameters. If it is determined during the scanning of a positionmark that the complete grid rests on the reference lines, it ensuresthat the respective slide-in unit 5 is positioned with sufficientaccuracy in the desired position. Thus, the needle 9 of thesample-taking device 8 is definitely positioned above the seal 3 andpunctures this seal. In particular, the dimensioning of the grid and thereference line elements 13 ensures that a slide-in unit 5 is not tiltedrelative to the straight line S that forms the desired position, whichwould hinder the insertion of needle 9 into the seal 3.

[0055] After a slide-in unit 5 is positioned in the desired position andthe position barcode 12 of the respective slide-in unit 5 is detected,the conveying system is halted and the optical sensor 10 switched to thesecond operating mode. The scanning range is then increased to the gridwith length Δy to detect the object barcode 14 of sample tube 2, whichis positioned in the slide-in unit 5 in the desired position. Thissituation is shown in FIG. 3.

[0056] Following detection of the position mark for slide-in unit 5 inthe desired position and the object mark of the respective sample tube2, the needle 9 of sample-taking device 8 is inserted into the sampletube 2 with the aid of the control unit and through the seal 3. Thesample taken in the process is analyzed in the blood-analysis machine 7.The analysis result is stored together with the previously determinedposition barcode 12 and the object barcode 14, so as to ensure that theanalysis result is clearly assigned to the sample tube 2 and this tubeis arranged inside the slide-in unit 5 of sample holder 4.

[0057] As soon as these operations are completed, the trigger signal forswitching to the first operating mode is generated in the control unit.At the same time, the control unit again starts the movement of theconveying system. Following this, the sample holder 4 is moved until thenext slide-in unit 5 is positioned in the desired position. In this way,all slide-in units 5 of sample holder 4 are successively positioned inthe desired position.

[0058]FIG. 4 shows the positioning of an empty slide-in unit 5 in thedesired position. The positioning is not completed since the grid forthe optical sensor 10 does not yet rest completely on the reference lineelements 13 of this slide-in unit 5.

[0059]FIG. 5 shows the slide-in unit 5 in the desired position, whereina switch to the second operating mode has already occurred followingdetection of the position barcode 12 at this slide-in unit 5. Since thisslide-in unit 5 is empty, the reference barcode 16 and not an objectbarcode 14 of a sample tube 2 is detected at the slide-in unit 5. As aresult, the evaluation unit for sensor 10 determines that the slide-inunit 5 is empty. In that case, a warning or error message is preferablygenerated in the evaluation unit, which indicates to the operatingpersonnel that the slide-in unit 5 is not occupied. Owing to the warningor error message, the sample-taking device 8 is also deactivated via thecontrol unit, thus keeping the needle 9 in the idle position to avoiddamages or malfunctions.

1. A device for positioning objects in a desired position, said devicecomprising a transmitter for emitting light rays (11), a receiver forreceiving light rays and an optical sensor (10) with evaluation unit,wherein the desired position is scanned with the transmitted light rays(11), the device further having at least one holding device in which apredetermined number of objects are stored in predetermined slide-inpositions and each slide-in position is characterized by a positionmark, further having a transport system (6) for moving the holdingdevice relative to the optical sensor (10), wherein the holding deviceis stopped as soon as the position mark for a slide-in position for apredetermined object is detected by the optical sensor (10) and whereinthe sensor (10) can identify the respective object through the objectmarks.
 2. A device according to claim 1, characterized in that theoptical sensor (10) is a barcode reader.
 3. A device according to one ofthe claims 1 or 2, characterized in that the holding device is a sampleholder (4), in which the sample tubes (2) that form the objects arestored in slide-in units (5) forming the slide-in positions.
 4. A deviceaccording to claim 3, characterized in that the sample tubes (2) storedinside the slide-in units (5) of the sample holder (4) are arrangedparallel and at a distance to each other, wherein the longitudinal axesof the sample tubes (2) extend transverse to the conveying direction ofthe sample holder (4).
 5. A device according to claim 4, characterizedin that the desired position extends along a straight line S, which runsparallel to the longitudinal axes of the sample tubes (2) stored insidethe sample holder (4).
 6. A device according to one of the claims 4 or5, characterized in that the transmitted light rays (11) of opticalsensor (10) are guided along the straight line S that forms the desiredposition.
 7. A device according to claim 6, characterized in that arectangular, flat grid is scanned with the transmitted light rays (11),wherein the straight line S that defines the desired position extendsinside this grid, in longitudinal direction of the grid.
 8. A deviceaccording to one of the claims 3-7, characterized in that the positionmarks are respectively arranged in the longitudinal axis of theassociated slide-in unit (5), on the side surface of sample holder (4)that is facing the optical sensor (10), wherein the position marks arerespectively arranged in the region of the lower end of a sample tube(2) stored in the respective slide-in unit (5).
 9. A device according toclaim 8, characterized in that each position mark is provided with aposition barcode (12) that contains the encoded number for the slide-inunit (5).
 10. A device according to one of the claims 8 or 9,characterized in that each position mark has two reference line elements(13), arranged at a distance to each other and one behind the other inlongitudinal direction of the slide-in unit (5), the longitudinal axesof which extend transverse to the longitudinal axis of slide-in unit(5).
 11. A device according to claim 9, characterized in that thereference line elements (13) of a position mark are arranged on bothsides of the position barcode (12) in its rest zone.
 12. A deviceaccording to one of the claims 10 or 11, characterized in that thelength of the reference lines elements (13) is shorter than the width ofthe grid scanned by the optical sensor (10).
 13. A device according toclaim 12, characterized in that the reference line elements (13) aredesigned to be identical.
 14. A device according to one of the claims8-13, characterized in that once a slide-in unit (5) is positioned inthe desired position, a needle (9) can be inserted through the seal (3)at the upper end of the sample tube (2) for taking a sample from thesample tube (2) stored inside the slide-in unit (5).
 15. A deviceaccording to claim 14, characterized in that the diameter of the seal(3) is larger than the length of the reference line elements (13).
 16. Adevice according to one of the claims 1-15, characterized in that theobject mark is an object barcode (14), affixed to the outside of asample tube (2), which contains the encoded content of sample tube (2).17. A device according to claim 16, characterized in that each slide-inunit (5) is provided with an opening (15) on the side facing the opticalsensor (10), through which the object barcode (14) is visible on asample tube (2) that is stored inside this slide-in unit (5).
 18. Adevice according to claim 17, characterized in that a reference barcode(16) for checking whether the slide-in unit (5) contains a sample tube(2) is arranged opposite the opening (15) on the inside of a slide-inunit, wherein the reference barcode (16) is visible through the opening(15) if the slide-in unit (5) is empty and is covered by the sample tube(2) if the slide-in unit (5) is occupied.
 19. A device according to oneof the claims 8-18, characterized in that in a first operating mode forpositioning a slide-in unit (5) in the desired position, a firstscanning range is scanned by the transmitted light rays (11) of opticalsensor (10), which range is adapted to the dimensions of the positionmarks, and that in a second operating mode where the slide-in unit (5)is in the desired position, this slide-in unit is scanned over itscomplete length inside a second scanning range.
 20. A device accordingto claim 19, characterized in that an slide-in unit (5) is in itsdesired position as soon as the complete width of the grid for thetransmitted light rays (11) is positioned on the reference line elements(13) of the respective position mark.
 21. A device according to claim20, characterized in that once the reference line elements of a positionmark are detected completely, a trigger signal is generated in theoptical sensor (10), which triggers a switch from the first to thesecond operating mode.
 22. A device according to one of the claims 20 or21, characterized in that the sample holder (4) is stopped if a slide-inunit (5) is in the desired position, so that following identification ofthe sample tube (2) that is stored inside the slide-in unit (5), theneedle (9) can be inserted into its seal (3) for taking a sample.
 23. Adevice according to claim 22, characterized in that an error or warningmessage is generated if a reference barcode (16) is detected in thesecond operating mode.
 24. A device according to one of the claims19-23, characterized in that an external trigger signal for switching tothe first operating mode can be read into the optical sensor (10).
 25. Adevice according to one of the claims 1-24, characterized in that thisdevice forms a component of an arrangement (1) for analyzing blood.